| 摘要 |
PROBLEM TO BE SOLVED: To provide a metal frame for casting a post with helical blades in which a core member can be positioned and fixed with respect to the metal frame even when the metal frame is not in a stationary state but is being rotated, in which a die can be rapidly set and attached/detached, and which can improve the safety. SOLUTION: The end face of a cylindrical metal frame 1 is made helical, the helix end face is extended in the radial direction to form a first helical surface 2, and a core member 5 has a helical surface facing the first helical surface 2 and a second helical surface 4 having a helical surface in the axial direction. Projections 10 and 11 which are brought into contact with each other at the predetermined position in the circumferential direction just before the first helical surface is brought into contact with the surface in the axial direction of the second helical surface in a facing manner when the metal frame 1 and the core member 5 are brought closer in the axial direction are provided on the inner surface of the axially extended cylindrical part 3 of the metal frame 1 and a part of the outer circumferential surface of the core member 5, respectively. The length of the projections in the axial direction is equal to the axial length in which the projection surfaces in the circumferential direction of the first helical surface 2 and the axial surface of the second helical surface 4 pass each other in the axial direction and lose contact each other just before the projection areas overlap when both projections are brought into contact with each other and the core member 5 is brought closer to the metal frame.
|
